The document EP 1 500 684 reports antistatic elastomeric compositions comprising a PEBA copolymer comprising PE blocks essentially made of PEG and PAX.Y blocks with X an aliphatic diamine, such as, for example, hexamethylenediamine and C9 to C25 diamines, and Y a C9 to C25 aliphatic diacid. These copolymers possessing antistatic properties do not come within the scope of our invention and are, of course, excluded as such.
The document EP 1 262 527 relates to an antistatic polymer composition comprising a PEBA of PAX.Y type with, as aliphatic diamine X: hexamethylenediamine, dodecamethylenediamine and trimethylhexamethylenediamine, and, as aliphatic diacid Y: butanoic acid, adipic acid, azelaic acid, suberic acid, sebacic acid, dodecanedicarboxylic acid, dimerized fatty acids and polyoxyalkylene-α,ω-diacids. The PE blocks made of PEG, which confer the antistatic properties on the copolymer and on the composition, can be used with PPG blocks, indeed even with PTMG blocks. These copolymers do not come within the scope of our invention and are, of course, excluded as such.
The document WO 03/050159 discloses PEBAs with, as hard segment, a PAX.Y block with X a linear aliphatic diamine comprising 4-14 carbon atoms and Y a linear aliphatic diacid comprising from 4 to 14 carbon atoms and with, as soft segment, PO3G, it being possible for the latter to comprise up to 60% by weight of another polyether, such as PEG, PPG and PTMG. These copolymers do not come within the scope of our invention and are, of course, excluded as such.
The document WO 04/037898 has as subject matter a copolymer comprising PA blocks and PE blocks, the PA blocks of which are copolyamides which can be of the PAX1.Y1/X2.Y2 or PAX1.Y1/Z type, X1 and X2 being diamines, Y1 and Y2 being diacids and Z being a lactam or an amino acid. These copolymers do not come within the scope of our invention and are, of course, excluded as such.
The Applicant Company has discovered, surprisingly, a novel category of PEBAs exhibiting improved optical properties, in particular a reduction in the opaqueness of the PEBAs, and/or improved mechanical properties, in particular a very good dynamic fatigue resistance.